This ARRA application represents an extension of RO1-44351, the first prospective cohort investigation of children with new onset epilepsy designed to characterize the etiology and natural history of neurodevelopmental abnormalities in cognition, brain structure, and psychopathology. Our long term goal is to understand the causes and earliest risk factors predictive of adverse quality of life outcomes of childhood onset epilepsy. This combined cross-sectional and longitudinal cohort study involves: a) a 6 year follow up of cognition, brain structure, and mental health of the initial cohort (75 children with new onset epilepsy and 62 healthy controls), b) enrichment of the cohort with 75 children with new onset epilepsy and 62 healthy controls, and c) the addition of new neuroimaging and cognitive procedures designed to address hypotheses regarding the neurobiology of critical cognitive and neurobehavioral comorbidities as well as the impact of epilepsy on cognitive and brain development. The specific aims of this application are: 1) Characterize the long term (6 year) course of cognitive development, brain maturation, and psychopathology associated with neurobehavioral comorbidities in new onset childhood epilepsy. 2) Identify the unique abnormalities in cortical morphology associated with neurobehavioral comorbidities in new onset epilepsy. 3) Characterize abnormalities in baseline cerebral white matter and the clinical significance of identified abnormalities in new onset epilepsy. 2.